Photo-bioreactor for mass production of photosynthetic organisms

ABSTRACT

The apparatus herein relates to the large-scale production of photosynthetic microorganisms, especially algae. More particularly it relates to control of large size aqueous photosynthetic bioreactor systems to obtain such products from many microbial strains, which have heretofore only been cultured in laboratory environments in small containers.

RELATED APPLICATION

The present application is a continuation of U.S. application Ser. No.14/821,867, filed Aug. 10, 2015, which was a continuation of U.S.Non-Provisional application Ser. No. 13/828,324, filed Mar. 13, 2013,now U.S. Pat. No. 9,315,767, issued Apr. 19, 2016, which was anon-provisional application of U.S. Provisional Application No.61/612,665 filed Mar. 19, 2012, all of which are hereby incorporatedherein in their entirety by reference.

FIELD OF THE INVENTION

The present invention is generally directed to a photo-bioreactor systemfor growing photosynthetic organisms. Specifically, the presentinvention is directed to a large scale photo-bioreactor system forproducing biomass harvested from photosynthetic organism.

BACKGROUND OF THE INVENTION

As there begins to be an increased need for the development of renewableenergy sources, the large scale production of algal bio-mass as means toproduce a transportation fuel is becoming a highly sought aftersolution. Thus numerous ventures around the world have been organized tosolve this problem. However, growing mass amounts of algae cheaply isdifficult, and there are many obstacles that have to be overcome, withone of the major ones being frequent contamination events.

Thus the need to design a photo-bioreactor, which can grow a robustaxenic culture, has become very apparent. When designing an effectivesolution, one also has to consider the many other contributing factors,such as energy balance, environmental impact, overall production rates,ease of harvest, capital expense, operating expense and, of course,sterility. An important factor for anyone attempting to develop arenewable fuel is keeping the overall energy balance of the productionsystem positive, while allowing the system to function optimally. Amajor energy sink for most photo-bioreactor systems is the need for acooling system. Maintaining an optimum temperature range (25° C.-39° C.)is crucial for the micro-organisms survival. Another factor that affectsthe energy balance of the system is the need for efficient CO₂ uptake.Being that CO₂ is an essential input to the production of autotrophicorganisms it becomes an expensive commodity to waste if it's not over 90percent utilized within the reactor.

SUMMARY OF THE INVENTION

A photo-bioreactor system, according to an embodiment of the presentinvention, comprises piping, valve work, control instrumentation, thenovel growth chamber and accompanying components, all which contributeto optimal large scale production of photosynthetic micro-organisms,especially algae and cyanobacteria. The growth chamber, of pyramidgeometry in this example embodiment, allows for optimum photonabsorption by the community of microbes residing within the chamber,while maximizing total volume per given area. The growth chamber, beingthe primary assembly, can be made of transparent plastic, whichencapsulates a volume of water, microbial culture, and necessarynutrient to produce biomass via photosynthesis. A support structuregives the photo-bioreactor its unique pyramid geometry, while allowingfor sunlight to penetrate into the reactor.

In this example embodiment, the closed system photo-bioreactor can becapable of growing volumes as great as 167,000 L per reactor andgreater, within a footprint of about 11.5 feet×200 feet or more.According to an embodiment of the present invention, the sixteenreactors can cover an area of approximately 1 sq. acre, as seen in FIG.2, and allow for the controlled production of up to 2.5 million litersof microbial culture per acre.

Assuming a conservative rate of oil production of about 0.033-0.053grams/liter/day, a rate that is easily produced by an algal species inautotrophic growth, an acre of land could therefore produce up to about42,000 L of bio-diesel per year, and an additional 84,000 kilograms ofde-wetted carbohydrates and proteins per year. These three main productscan be accompanied by myriad of other high value products such asPolyunsaturated Fatty Acids (PUFAs), such as Omega-3s, which areessential for good health, plastic resins such as PHA and PHB,beta-carotene, as well as other chemical and pharmaceutical compounds.In addition, there is still substantial room for improvement of yieldsthrough optimization, as the previous numbers represent only examples ofattained production yields.

The inventive concept described herein relies on the nature of certainspecies to flocculate, and settle out of solution, along the bottomsurface of the growth chamber. A mechanism enables the harvest apparatusto roll back and forth along the floor of the growth chamber and collectthe settled biomass. Suction created by the harvest pump is transferredthrough the manifold found along the length of the apparatus, and downalong the floor of the harvest chamber. Two guide cables found on eitherside of the apparatus, guide the harvest apparatus along the length ofthe photo-bioreactor. As it comes in contact with the opposing wall ofthe reactor, a switch mechanism can be employed to reverse direction ofmotion of the apparatus and cause it to move in the opposite direction.

In another example embodiment, a flocculent can be utilized to inducesettling for microbial strains that are more resistant to flocculationand settling.

Thus, the attributes that make this a unique apparatus are thefollowing: Firstly, the pyramid shape of the reactor allows for greaterpenetration of photons into the growth chamber. The unique geometry ofthe reactor in combination with the placement of the air sparger systemsub-assembly provides greater turbulence in the photo-bioreactor, andenables the reactor to grow a larger volume per given square meter thana point source mixing technique. The disclosed closed photo-bioreactorsystem could be capable of efficiently growing enormous volumes ofculture at great concentrations while preserving valuable resources suchas water.

The unique geometry of the example reactor in combination with theunique placement of the air sparger system sub-assembly also helpsprevent the accumulation of bio-film along the inner surface walls ofthe photo-bioreactor, therefore allowing for maximum light penetration,and hence for optimum productivity via photosynthesis.

The filtration system, on the intake and exhaust sides of thephoto-bioreactor system as seen in FIG. 1, helps to ensure sterility ofthe photo-bioreactor. Having an exhaust filter in place as a method ofdeterring contamination is a unique practice, and is an effective methodin preventing contamination in the event of system pressure loss.

The return CO2 line, in combination with the method of diffusing CO2,improves the efficient use of CO2, and prevents waste CO2 from beinglost into the atmosphere. This aspect overcomes a major obstacle that isimportant in achieving a photosynthetic system for production ofrenewably energy.

The nutrient delivery method, as well as construction technique are veryunique to closed photo-bioreactor systems, and allow for evendistribution of nutrient throughout the growth chamber, and promote evengrowth throughout the reactor.

The unique harvest apparatus design, is unlike any other device utilizedin algal cultivation, and in combination with the novel growth chamberdesign, allows for very efficient harvest of biomass, which not onlysaves the algae growth operation hours in harvest time, but alsodrastically reduces operating expenses.

Lastly, the sheer volume of the culture within the reactor incombination with the air system, make a cooling system unnecessary, thuseliminating a large energy expense.

Therefore, the unique combination of sub-assemblies in conjunction withoperation regime and novel photo-bioreactor geometry as described above,allow for a new method of large-scale algal cultivation.

A photo-bioreactor system for growing photosynthetic organisms toproduce biomass, according to an embodiment of the present invention,can comprise a tubular growth chamber, a movable harvest manifold and aharvest pump for drawing a vacuum through the harvest manifold. Thetubular growth chamber further comprises a plurality of elongatedtransparent panels arranged edgewise such that the tubular growthchamber comprises a generally flat bottom and at least two angled sidesintersecting an apex and two end panels affixed to the ends of theplurality of elongated transparent panels to enclose the tubular growthchamber. In certain aspects, at least one of the end panels comprises atleast one flanged component port for receiving sampling instrumentationfor evaluating conditions within the tubular growth chamber. In certainembodiments, a support structure comprising a plurality of intersectingbeams that can be overlaid on top of the tubular growth chamber tosupport the elongated panels. In certain aspects, a steel mesh or cagecan be positioned in the gaps between the intersecting beams toreinforce and protect the transparent panels while not obstructing lightpassing between the beams. The tubular growth chamber can receive water,microbial cultures of photosynthetic organisms and nutrient solutions.

The harvest manifold is movable along the flat bottom of the tubulargrowth chamber and can comprise a plurality of hollow fingers throughwhich a vacuum can be drawn by the vacuum pump to draw biomass settledon the flat bottom of the tubular grow chamber into the harvest manifoldfor collection. In certain aspects, the harvest manifold can furthercomprise at least one motor driven wheel engagable to the flat bottom tomove the harvest manifold along the flat bottom of the tubularbioreactor. In this configuration, the tubular growth chamber canfurther comprise at least one guide wire extending between the endpanels, wherein the harvest manifold further comprises a flanged fittingslidingly engagable to the guide wire to maintain the harvest manifoldin a generally parallel orientation to the end panels as the harvestmanifold is moving along the flat bottom.

In certain aspects, the photo-bioreactor system can further comprise atleast one nutrient delivery tube extending along the apex of the tubulargrowth chamber and further comprising a plurality of perforations alongthe delivery tube for dispensing nutrients at the apex of the tubulargrowth chamber. The positioning of the nutrient delivery tube proximatethe apex of the tubular growth chamber ensures that the deliverednutrients are evenly dispersed throughout the tubular growth chamber.

In certain embodiments, the photo-bioreactor system can further compriseat least one air sparger extending along the intersection of one of thesides and the bottom, wherein the air sparger comprises a plurality ofperforations for expelling air into the tubular bioreactor from the airsparger. The perforations in the air sparger are oriented to direct theexpelled air against the angled sides of the tubular bioreactor suchthat the air runs up the sides of the tubular bioreactor to dislodgebiomass adhered to the sides. The air flow along the sides of thetubular bioreactor also serves to cool the bioreactor without the aid ofseparate cooling system.

In certain embodiments, the photo-bioreactor system can further comprisean exhaust assembly operably linked to the tubular bioreactor proximatethe apex for receiving exhaust gas from the tubular bioreactor andcomprising a selectable filter assembly. The selectable filter assemblycan redirect the exhaust gas into the bioreactor if carbon dioxide isdetected in the exhaust gas and venting the exhaust gas to atmosphere ifno carbon dioxide is detected. In certain aspects, the exhaust assemblycan further comprise a chimney component extending from the apexincreasing headspace within the tubular bioreactor. The chimneycomponent comprises an upper portion on which condensation can form andthe chimney component comprises a vapor collection port, wherein theupper portion of the chimney component is angled to direct condensateinto the vapor collection port.

A method of producing biomass from photosynthetic microorganisms,according to an embodiment of the present invention, can compriseproviding a tubular growth chamber comprising a plurality of end panelsand a plurality of elongated transparent panels arranged edgewise todefine a generally flat bottom and at least two angled sidesintersecting an apex. The method can further comprise filling thetubular growth chamber with a volume of water, at least one microbialculture of photosynthetic organisms and a nutrient solution, wherein thetransparent panels allow entry of light to enter the tubular growthchamber to initiate microbial growth of the photosynthetic organisms.After growth of microbial culture, the method can also comprise moving aharvest manifold along the flat bottom of the tubular reactor andcomprising a plurality of hollow fingers. Finally, the method cancomprise drawing a vacuum through the hollow fingers to draw biomasssettled on the flat bottom of the tubular grow chamber into the harvestmanifold for collection.

In certain embodiments, the method can also comprise positioning atleast one nutrient delivery tube along the apex of the tubular growthchamber, wherein the nutrient delivery tube comprises a plurality ofperforations and dispensing a nutrient solution through the perforationsof the nutrient delivery tube to evenly distribute the nutrient solutionthroughout the tubular bioreactor. Similarly, the method can alsocomprise positioning at least one air supply along intersection of theangled sides and flat bottom of the tubular growth chamber, wherein theair sparger comprises a plurality of perforations and directing an airstream through the perforations in the air sparger such that the airstreams up the sides of the tubular bioreactor to dislodge biomassadhered to the sides.

In certain embodiments, the method can further comprise sampling thecarbon dioxide in the tubular bioreactor through a flanged port in theend panels of the tubular bioreactor and increasing air delivered to thebioreactor if the carbon dioxide falls beneath a predeterminedthreshold.

In certain embodiments, the method can further comprise linking anexhaust assembly to the apex of the tubular bioreactor, wherein theexhaust assembly further comprising a selectable filter assembly. Themethod can also comprise receiving a quantity of exhaust gas from thetubular bioreactor and returning the exhaust gas to the tubularbioreactor if the selectable filter assembly detects carbon dioxide inthe exhaust gas. Similarly, the method can also comprise affixing achimney to the apex of the tubular bioreactor to increase headspacewithin the tubular reactor, the chimney comprising an upper portionangled toward a vapor collection port and collecting condensation on theupper portion, wherein the angled upper portion directs the condensationtoward the vapor collection port.

The above summary of the various representative embodiments of theinvention is not intended to describe each illustrated embodiment orevery implementation of the invention. Rather, the embodiments arechosen and described so that others skilled in the art can appreciateand understand the principles and practices of the invention. Thefigures in the detailed description that follow more particularlyexemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be completely understood in consideration of thefollowing detailed description of various embodiments of the inventionin connection with the accompanying drawings, in which:

FIG. 1 shows an overall view of how a photo-bioreactor fits in with itsoperating system according to an embodiment of the present invention.

FIG. 2 depicts a scaled representation of a 1 acre layout containing 16photo-bioreactors.

FIG. 3 depicts a support structure for a photo-bioreactor chamberaccording to an embodiment of the present invention.

FIG. 4 depicts the front view of a growth chamber and its innercomponents according to an embodiment of the present invention.

FIG. 5 depicts the back/side view of a growth chamber and its attachedinner components according to an embodiment of the present invention.

FIG. 6 depicts a close-up view of a harvest apparatus and air spargerline according to an embodiment of the present invention.

FIG. 7 depicts a close-up view of a nutrient delivery line according toan embodiment of the present invention.

FIG. 8 depicts a view from inside a growth chamber of a harvestapparatus.

FIG. 9a depicts the front view of the current embodiment in which theturbulent flow path can be seen, as well as the overall fluid level ofthe culture.

FIG. 9b depicts the front view of another possible embodiment andrelated chamber geometry, in which the turbulent flow path can be seen,as well as the overall fluid level of the culture.

FIG. 9c depicts the front view of yet another possible embodiment andrelated chamber geometry, in which the turbulent flow path can be seen,as well as the overall fluid level of the culture

FIG. 10 depicts a flow diagram of the process in relation to the novelphoto-bioreactor. The dashed lines in the FIG. 10 represent electricalconnections of said components to the control system and elucidate theremote control abilities of the system.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION

As depicted in FIG. 1, a component 100, according to an embodiment ofthe present invention, is a transparent, heat weld-able plasticmaterial, 5-20 mils thick, and heat welded along the perimeter to makeit a fully enclosed pyramid shape growth chamber. The material ofconstruction can be a film composed of LDPE, PHA, KYNAR or any othercomposite film that is heat weld-able. In this example embodiment, thedimensions of the growth chamber, as depicted in FIG. 4, can be asfollows: X could be between 4 ft to 16 ft, Y could be between 2 ft to 8ft, and Z could be between 4 ft to 400 ft. In certain embodiments, thecomponent 100 can comprise a plurality of elongated panels connectededgewise to define a tubular configuration, wherein two end panels sealthe ends of the bioreactor. In certain aspects, the elongated panels canbe arranged such that the tubular configuration comprises a generallytriangular configuration.

As depicted in FIG. 9b , in certain aspects, the component 100 asdepicted in FIG. 9b , has a different geometry that increases theheadspace above the fluid level, thus increasing the volume of watervapor. This geometry could be applicable for harvest of ethanol vaporthrough the Exhaust Air/Return CO2 line, as depicted in FIG. 1.

As depicted in FIG. 9c , in certain aspects, component 100 as depictedin FIG. 9c , has a different geometry that increases the headspace abovethe fluid level, and also increases the overall surface area of plasticnot in contact with the culture. The increase in headspace incombination with the increase in surface area above the fluid level,allows for more condensation to form on the sides of the reactor. TheV-geometry of the upper portion of the reactor, as depicted in FIG. 9c ,would cause condensate to develop on the inner wall of the growthchamber within the reactor, and drip down into the vapor collectiongutter, which would be built on a slope to cause the condensate to flowtowards vapor collection port, and collected for processing. Thisgeometry could be applicable for harvest of ethanol vapor through thevapor collection port as depicted in FIG. 9 c.

As depicted in FIG. 3, the support structure provides a pyramidalgeometry allowing sunlight to penetrate into the reactor. In certainaspects, component 50 can comprise a steel beam of 2 in×2 in crosssection, such as UNISTRUT steel beam, and is connected at intersectionsvia steel weld, or UNISTRUT fittings. As depicted in FIG. 3, component52 can be a steel cage, cut to fit appropriate dimensions. The cell sizeof the cage (component 52) can be range in size from 2 in×2 in to 6 in×6in.

Components 110,120, 130, 140, 150, 152, 154, 156, 160, 166 and 214 areplastic fittings that can be flanged, and have various sizes, andterminal ends. Components 110,120, 130, 140, 150, 152, 154, 156, 160,166 and 214 are connected to component 100 via heat weld. Materialsother than plastic or steel, such as aluminum, that are sturdy andstrong can also be used in any of the various embodiment describedherein.

1. Intake Air System

According to an embodiment of the present invention, the intake airsystem consisting of components 110-118, also includes an air-blower,piping, control valves, filtration, and an air sparger found within thechamber.

Component 114 is an intake air filter of pore size of about 0.2 um to 1um which can be connected to component 112 via a tri-clover connection,silicone gasket, and tri-clover clamp. Component 112 can be a siliconeline of about 2 in to 4 in in diameter with a tri-clover fitting at bothof its terminals, and connected to component 110, via a tri-cloverconnection, silicone gasket, and tri-clover clamp. Component 110 can bea two sided, flanged, plastic fitting, of about 2 in to 4 in indiameter, with a tri-clover connection on the exterior end, and acylindrical sleeve on the interior end. Component 110 connects tocomponent 100 via heat-weld, producing a port from the exterior side ofthe growth chamber to the interior. On the interior side, component 110can be connected to component 116 via heat weld, as depicted in FIG. 6,and represented by a dashed line. As depicted in FIG. 5, component 116is the air sparger found within the growth chamber, and can be composedof transparent (or translucent), heat weld-able plastic material (orPlexiglas or glass), 5-20 mils thick, and heat welded along theperimeter to make it a fully enclosed tube. As depicted in FIGS. 5 and6, component 116 can be perforated along its length. As depicted in FIG.6, the distance between each orifice can range from about 2 in to 24 in,represented by distance D, and the diameter of each orifice (component118) can be about 1/64 in to ¼ in.

As depicted in FIG. 5, component 116 runs the length of the growthchamber and reconnects via heat weld to component 110 found on theopposite end of the growth chamber. Component 110 can be a two sided,flanged, plastic fitting with a tri-clover connection on the exteriorend, and a cylindrical sleeve on the interior end. Component 110, again,connects with component 112 via a tri-clover connection, siliconegasket, and tri-clover clamp. Component 112 can be a silicone line of 2in to 4 in in diameter with a tri-clover fitting at both of itsterminals, and can connect to component 114 via a tri-clover connection,silicone gasket, and tri-clover clamp.

2. Exhaust Air/Return CO₂

According to an embodiment of the present invention, the exhaustair/return CO2 system consists of components 120-124, and allows for theexhaust of intake air. Other than the components directly attached tothe growth chamber, the system also contains additional plumbing,filtration, control valves, and instrumentation to accomplish severaljobs

As depicted in FIG. 4, component 120, which can be a flanged, plastictri-clover fitting of diameter of about 1 in to 4 in, is connected tocomponent 100 via heat weld. Component 120 is then connected tocomponent 122 via a tri-clover connection, silicone gasket, andtri-clover clamp. Component 122 can be a silicone line of about 1 in to4 in in diameter with a tri-clover fitting at both of its terminals, andconnected to component 124, via a tri-clover connection, siliconegasket, and tri-clover clamp. Component 124 can be an exhaust air filterof pore size 0.2 um to 1 um. The air, and/or, CO2 mixture being purgedthrough the exhaust filter has the option of returning back to theblower if CO2 is detected in the growth chamber, or to be purged intothe atmosphere if no CO2 has been detected.

3. Water Delivery

According to an embodiment of the present invention, the water deliverysystem consists of additional plumbing and infrastructure such ascontrol valves, CIP plumbing, and flow meters, and allows for controlleddelivery of medium into the growth chamber. Component 130 can be used asthe method of supplying an aqueous solution to the apparatus.

Component 130, as depicted in FIG. 4, can be a flanged, plastictri-clover fitting of diameter of about 1 in to 4 in and is connected tocomponent 100 via heat weld. Additional plumbing, for seawater, or freshwater can be connected to component 130 via a tri-clover connection,silicone gasket, and tri-clover clamp. Component 130 can also be used asan entry point for CIP through system plumbing.

4. Nutrient Delivery

According to an embodiment of the present invention, the nutrientdelivery system, consisting of components 140-144, allows for evendistribution of nutrient throughout the entire length of the reactor,thus eliminating uneven concentrations of nutrient within the system.The system consists of additional plumbing and infrastructure such ascontrol valves, CIP plumbing, and flow meters, and allows for controlleddelivery of nutrient into the growth chamber.

Component 140, as depicted in FIG. 4 and FIG. 7, can be a two sided,flanged, plastic fitting with diameter of about 1 in to 4 in, with atri-clover connection on the exterior end, and a cylindrical sleeve onthe interior end, and can be connected to component 100 via heat weld.

On the interior side, component 140 can be connected to component 142via heat weld, as depicted in FIG. 7. Component 142 is perforatednutrient delivery tube found within the growth chamber, and can becomposed of transparent, heat weld-able plastic material, about 5-20mils thick, and heat welded along the perimeter to make it a fullyenclosed tube. Component 142 can be attached to component 100 via heatweld along its entire length. As depicted in FIGS. 5 and 7, Component142 can be perforated along its entire length. As depicted in FIG. 7,the distance between each orifice is represented by letter G, and canrange from about 2 in-24 in. As depicted in FIG. 7, the diameter of eachorifice can be about 1/64 in-¼ in.

As depicted in FIG. 5, at the opposite side of the growth chamber,component 142 connects to, component 144 via heat weld. Component 144,as depicted in FIG. 5, can be a flanged plastic fitting with acylindrical sleeve of diameter of about 1 in to 4 in, facing theinterior of the growth chamber, but having no through opening. Inanother embodiment, component 144 can be a two sided, flanged, plasticfitting with diameter of about 1 in 4 in, with a tri-clover connectionon the exterior end, and a cylindrical sleeve on the interior end, andcapped on the exterior end to prevent flow through.

5. Control Instrumentation

According to an embodiment of the present invention, the controlInstrumentation, which contains components 150-156, consists ofinstrumentation that is configured for delivering data such astemperature, pH, and CO2 levels within the chamber. An ability toascetically sample from the reactor is also built into this system. Theinstrumentation is an integral part of being able to control and measurethe levels of CO2 being delivered into the system, thus maintainingoptimal growth, and using up to 90% of the CO2 without wasting thisimportant ingredient. All information is routed through the control box.

Component 150, as depicted in FIG. 4, can be a flanged plastic fittingwith a hose barb of/4 in to 1 in in diameter, and connected to component100 via heat weld. Additional assemblies can be added to the hose barb,such as 1 ft 4 in to 1 in ID silicone tubing with a clamp, and a plug.This assembly, beginning with component 150, comprises the sampling portof the growth chamber, and can be used for as an alternative port foradditions and inoculations.

Component 152, as depicted in FIG. 4, can be a flanged, plastictri-clover fitting of diameter of ¾ in to 4 in, and is connected tocomponent 100 via heat weld. Component 152 allows for insertion ofinstrumentation such as a temperature probe, pH probe, or oxygen sensor.The instrumentation can be adapted to fit a tri-clover fitting, andconnect to component 152 via a tri-clover connection, silicone gasket,and tri-clover clamp.

Component 154, as depicted in FIG. 4, can be a flanged, plastictri-clover fitting of diameter of ¾ in to 4 in, and is connected tocomponent 100 via heat weld. Component 154 allows for insertion ofinstrumentation such as a temperature probe, pH probe, or oxygen sensor.The instrumentation can be adapted to fit a tri-clover fitting, andconnect to component 154 via a tri-clover connection, silicone gasket,and tri-clover clamp.

Component 156, as depicted in FIG. 4, can be a flanged, plastictri-clover fitting of diameter of ¾ in to 4 in, and is connected tocomponent 100 via heat weld. Component 156 allows for insertion ofinstrumentation such as a CO2 sensor. The instrumentation can be adaptedto fit a tri-clover fitting, and connect to component 156 via atri-clover connection, silicone gasket, and tri-clover clamp.

Instrumentation connected to the growth chamber, can be connected to thecontrol box as depicted in FIG. 1, and used to relay data to the controlcenter. Electrical connections of instruments to control box aredepicted in FIG. 10.

6. Control Instrumentation

According to an embodiment of the present invention, the harvestplumbing sub-assembly, consisting of components 160-166, connects theharvest apparatus to a harvest pump and further harvest and CIPinfrastructure such as plumbing and control valves. The harvest plumbingfacilitates the removal of concentrated biomass from thephoto-bioreactor via specialized harvest apparatus.

Component 160, as depicted in FIG. 4 and FIG. 5, can be a two sided,flanged, plastic fitting, 1 in to 4 in in diameter, with a tri-cloverconnection on both the exterior end, and the interior end. Component 160is connected to component 100 via heat weld. On the exterior side of thegrowth chamber, as depicted in FIG. 4, component 160 is connected tocomponent 162, via a tri-clover connection, silicone gasket, andtri-clover clamp. Component 162 can be a silicone line of 1 in to 4 inin diameter with a tri-clover fitting at both of its terminals, and canbe connected to a pump and additional CIP/harvest plumbing and valvework.

On the interior side of the chamber, component 160, as depicted in FIG.5, can be connected to component 164 via a tri-clover connection,silicone gasket, and tri-clover clamp. Component 164, as depicted inFIG. 5, can be a silicone line of 1 in to 4 in in diameter, with atri-clover fitting at both of its terminals, and can be connected to theharvest apparatus' inlet port, which is component 210, via a tri-cloverconnection, silicone gasket, and tri-clover clamp.

Component 166, as depicted in FIG. 4, is an additional port designatedfor harvest of the entire volume of culture within the culture chamber.Component 166, can be a flanged plastic fitting with a tri-cloverterminal of 1 in to 4 in in diameter, and connected to component 100 viaheat weld. Component 166 can connect directly to harvest plumbing asdepicted in FIG. 1.

7. Harvest Apparatus

In this example embodiment, the harvest apparatus, which consists ofcomponents 200214, allows for efficient removal of concentrated biomass,thus saving on the amount of water needed to produce biomass. Theapparatus also reduces time spent harvesting biomass from the reactor,by reducing reactor re-fill times and a de-wetting of biomass.

Component 200, as depicted in FIGS. 5, 6 and 8, is a driving mechanismfor the harvest apparatus. Component 200 can contain a motor, whichdrives the entire harvest apparatus forwards and backwards. Component200 can also be driven by the suction force being created across amechanism, which creates torque, which can be transferred to the wheelsof the apparatus (components 208) and thus drive the harvest apparatusforwards and backwards. Component 200 rests on top of the harvestapparatus, and can be connected to component 202 via clip in mechanism,plastic screws, or heat weld.

As depicted in FIG. 6, component 210 can be a flanged, plastictri-clover fitting with diameter of 1 in to 4 in and can be attached tocomponent 202 via heat weld. Component 210 serves as the connectionpoint between the harvest apparatus, and the harvest plumbing, which iscomprised of components 160-164, and can be connected to the harvestplumbing (component 164), via a tri-clover connection, silicone gasket,and tri-clover clamp. Component 210 allows for the transfer of suctionpressure created by a harvest pump, through the harvest pump, and acrossa manifold chamber signified by component 202.

Component 202, as depicted in FIG. 8, is a hollow, plastic chamber,which makes up the top portion of the suction manifold of the harvestapparatus, and distributes the suction pressure across its length andinto the components 204 (20 total as depicted in FIG. 8). Components204, can be made of plastic material, and are narrow, hollow fingers,which are design to collect settled biomass from the growth chamberfloor via suction pressure created by the harvest pump.

Component 206, as depicted in FIGS. 6 and 8, is plastic guidepost, whichcan be made of plastic material, and be connected to component 202 viaheat weld. Component 206 contains an eyelet through which component 212passes. Component 212 is a guide cable, which can be coated with aplastic material, and is connected on either end of the growth chamberto component 214 via heat weld. Component 214, as depicted in FIG. 6,can be a flanged fitting that contains a hooking device on the exteriorside of the growth chamber, thus allowing one to fasten the ends ofcomponent 214, and apply tension to the guide cables (components 212),hence creating two taunt guide lines running the length of the growthchamber to guide the harvest apparatus.

According to an embodiment of the present invention, a smaller harvestpump can be located inside the growth chamber, directly above component210, such that the suction force is applied directly through the port210, and into the collection manifold 202.

In an example embodiment of the present invention, the contributingsubassemblies to the primary growth chamber comprise the intake airsystem consisting of components 110-116; Exhaust Air/CO2 Return, whichconsists of components 120-124; water delivery which consists ofcomponent 130; Nutrient delivery, which consists of components 140-144;Control Instrumentation which contains components 150-156; Harvestplumbing, consisting of components 160-166; and Harvest apparatus, whichconsists of components 200-214.

The intake air system, consisting of components 110-116 in this exampleembodiment, also includes an air-blower, piping, control valves,filtration, and an air sparger found within the chamber. These partsallow for clears delivery of air into the growth chamber thus providingsufficient turbulence within the growth chamber, which results in anincrease in circulation, and develops a turnover rate that increasescellular exposure to sunlight (or artificial light). A cross sectionalfront view of the reactor that depicts the turbulent flow path caused bythe aeration system can be seen in FIG. 9a . This aeration of culturealso results in an essential de-oxygenation of the microbial culture,thus increasing overall productivity.

Another key characteristic of the air system, of this exampleembodiment, in relation to the geometry of the photo-bioreactor is thepath that the curtain of air is forced to take along the inner surfaceof the reactor, as seen in FIG. 9a . This path allows for the scouringof the inner surface by the small air bubbles, which in turn eliminatethe accumulation of bio-film.

The intake air may be coupled with a CO2 source, which may be injectedinto the intake air-system just prior to the intake filter, andtherefore mixed with the culture as it is bubbled through the airsparger. This allows for the CO2 to become diffuse into the culture, andtake the form of carbonic acid. In this manner, the CO2 becomesavailable for utilization by the photosynthetic microbes

The Exhaust Air/Return CO2 system consists of components 120-124 in thisexample embodiment and allows for the exhaust of intake air. Other thanthe components directly attached to the growth chamber, the system alsocontains additional plumbing, filtration, control valves, andinstrumentation to accomplish several tasks. The first is to cleanlyexhaust the intake air without compromising sanitation of the culturewithin the chamber. The second allows for a return loop to remediate anyun-used CO2, and return it back into the growth chamber. The return loopfeature of the apparatus also allows one to capture any valuableproducts being vaporized by culture within the growth chamber, such asethanol for example.

The water delivery system, of this example embodiment, consists ofadditional plumbing and infrastructure such as control valves, CIPplumbing, and flow-meters, and allows for controlled delivery of mediuminto the growth chamber. Component 130 may be used as the entry pointfor water delivery into the growth chamber.

The nutrient delivery system, of this example embodiment, consisting ofcomponents 140-144 and allows for even distribution of nutrientthroughout the entire length of the reactor, thus eliminating unevenconcentrations of nutrient within the system. The system consists ofadditional plumbing and infrastructure such as control valves, CIPplumbing, and flow meters, and allows for controlled delivery ofnutrient into the growth chamber.

The control Instrumentation, of this example embodiment, which containscomponents 150-156, consists of instrumentation that is configured fordelivering data such as temperature, pH, and CO2 levels within thechamber. An ability to ascetically sample from the reactor is also builtinto this system injected into the intake air-system just prior to theintake filter and therefore mixed with the culture as it is bubbledthrough the air sparger. This allows for the CO2 to become diffuse intothe culture, and take the form of carbonic acid. In this manner, the CO2becomes available for utilization by the photosynthetic microbes

The Exhaust Air/Return CO2 system consists of components 120-124 in thisexample embodiment and allows for the exhaust of intake air. Other thanthe components directly attached to the growth chamber, the system alsocontains additional plumbing, filtration, control valves, andinstrumentation to accomplish several tasks. The first is to cleanlyexhaust the intake air without compromising sanitation of the culturewithin the chamber. The second allows for a return loop to remediate anyun-used CO2, and return it back into the growth chamber. The return loopfeature of the apparatus also allows one to capture any valuableproducts being vaporized by culture within the growth chamber, such asethanol for example.

The water delivery system, of this example embodiment, consists ofadditional plumbing and infrastructure such as control valves, CIPplumbing, and flow-meters, and allows for controlled delivery of mediuminto the growth chamber. Component 130 may be used as the entry pointfor water delivery into the growth chamber.

The nutrient delivery system, of this example embodiment, consisting ofcomponents 140-144 and allows for even distribution of nutrientthroughout the entire length of the reactor, thus eliminating unevenconcentrations of nutrient within the system. The system consists ofadditional plumbing and infrastructure such as control valves, CIPplumbing, and flow meters, and allows for controlled delivery ofnutrient into the growth chamber.

The control instrumentation, of this example embodiment, which containscomponents 150-156, consists of instrumentation that is configured fordelivering data such as temperature, pH, and CO2 levels within thechamber. An ability to ascetically sample from the reactor is also builtinto this system. The instrumentation is an integral part of being ableto control and measure the levels of CO2 being delivered into thesystem, thus maintaining optimal growth while using the CO2 withoutwasting this important ingredient. All information is routed through thecontrol box.

The harvest plumbing, of this example embodiment, consisting ofcomponents 160-166 and connects the harvest apparatus to a harvest pumpand further harvest and C infrastructure such as plumbing and controlvalves. The harvest plumbing facilitates the removal of concentratedbiomass from the photo-bioreactor via a specialized harvest apparatus.

The harvest apparatus, of this example embodiment, which consists ofcomponents 200-214, allows for efficient removal of concentratedbiomass, thus saving on the amount of water needed to produce biomass.The apparatus also reduces time spent harvesting biomass from thereactor, by reducing reactor re-fill times, a de-wetting of biomass.

The following patents and publications are incorporated herein byreference in their entirety: U.S. Publication number 2011/0104790; andU.S. Pat. Nos. 7,770,322 and 5,541,056.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and described in detail. It is understood, however, that theintention is not to limit the invention to the particular embodimentsdescribed. On the contrary, the intention is to cover all modifications,equivalents, and alternatives falling within the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. A photo-bioreactor system for producing biomasscomprising: a growth chamber comprising: a plurality of elongatedtransparent panels arranged edgewise; a flat bottom; two end panelsaffixed to the plurality of elongated transparent panels to enclose thegrowth chamber, wherein the growth chamber forms a continuous enclosedspace; a harvest manifold movable along the flat bottom of the growthchamber, wherein the harvest manifold further comprises at least onemotor driven wheel engageable to the flat bottom of the growth chamberto move the harvest manifold along the flat bottom of the growthchamber, wherein a suction created by a harvest pump is transferredthrough the harvest manifold; and a flexible air sparger extending alongan intersection of at least one of the plurality of elongatedtransparent panels and the flat bottom.
 2. The photo-bioreactor systemfor producing biomass of claim 1, wherein the flexible air spargercomprises a plurality of perforations that expel air into the growthchamber.
 3. The photo-bioreactor system for producing biomass of claim2, wherein the plurality of perforations each independently are orientedto direct the air against the plurality of elongated transparent panelsof the photo-bioreactor system.
 4. The photo-bioreactor system forproducing biomass of claim 2, wherein the plurality of perforations eachindependently are separated from each other by a distance from about 2inches to about 24 inches.
 5. The photo-bioreactor system for producingbiomass of claim 2, wherein the plurality of perforations eachindependently have a diameter from about 1/64 inches to about ¼ inches.6. The photo-bioreactor system for producing biomass of claim 1, whereinthe flexible air sparger comprises a heat weldable plastic material thatis heat welded to the growth chamber along a perimeter of the flexibleair sparger.
 7. The photo-bioreactor system for producing biomass ofclaim 1, wherein the harvest pump is located inside the growth chamberand is attached to the harvest manifold so that the suction is appliedto the harvest manifold.
 8. A photo-bioreactor system for producingbiomass comprising: a tubular growth chamber comprising: a plurality ofelongated transparent panels arranged edgewise, wherein at least twoangled sides of the elongated transparent panels intersect at an apex; aflat bottom; two end panels affixed to the plurality of elongatedtransparent panels to enclose the tubular growth chamber, wherein thetubular growth chamber forms a continuous enclosed space; a harvestmanifold movable along the flat bottom of the tubular growth chamber,wherein the harvest manifold further comprises at least one motor drivenwheel engageable to the flat bottom of the growth chamber to move theharvest manifold along the flat bottom of the growth chamber, wherein asuction created by a harvest pump is transferred through the harvestmanifold; and a flexible air sparger extending along an intersection ofone of the two angled sides and the flat bottom.
 9. The photo-bioreactorsystem for producing biomass of claim 8, wherein the flexible airsparger comprises a plurality of perforations that expel air into thetubular growth chamber.
 10. The photo-bioreactor system for producingbiomass of claim 9, wherein the plurality of perforations eachindependently are oriented to direct the air against the angled sides ofthe photo-bioreactor system.
 11. The photo-bioreactor system forproducing biomass of claim 8, wherein the flexible air sparger comprisesa heat weldable plastic material that is heat welded along a perimeterof the flexible air sparger.
 12. The photo-bioreactor system forproducing biomass of claim 8, wherein the harvest pump is located insidethe tubular growth chamber and is attached to the harvest manifold sothat the suction is applied to the harvest manifold.
 13. Aphoto-bioreactor system for producing biomass comprising: a triangularprism-shaped growth chamber comprising: a plurality of elongatedtransparent panels arranged edgewise, wherein at least two angled sidesof the elongated transparent panels intersect a t an apex; a flatbottom; two end panels affixed to the plurality of elongated transparentpanels to enclose the triangular prism-shaped growth chamber, whereinthe triangular prism-shaped growth chamber forms a continuous enclosedspace; a harvest manifold movable along the flat bottom of thetriangular prism-shaped growth chamber, wherein the harvest manifoldfurther comprises at least one motor driven wheel engageable to the flatbottom of the growth chamber to move the harvest manifold along the flatbottom of the growth chamber, wherein a suction created by a harvestpump is transferred through the harvest manifold; and a flexible airsparger extending along an intersection of one of the two angled sidesand the flat bottom.
 14. The photo-bioreactor system for producingbiomass of claim 13, wherein the flexible air sparger comprises aplurality of perforations that expel air into the triangularprism-shaped growth chamber.
 15. The photo-bioreactor system forproducing biomass of claim 14, wherein the plurality of perforationseach independently are oriented to direct the air against the angledsides of the photo-bioreactor system.
 16. The photo-bioreactor systemfor producing biomass of claim 13, wherein the flexible air spargercomprises a heat weldable plastic material that is heat welded along aperimeter of the flexible air sparger.
 17. The photo-bioreactor systemfor producing biomass of claim 13, wherein a harvest pump is locatedinside the triangular prism-shaped growth chamber and is attached to theharvest manifold so that the suction is applied to the harvest manifold.